FOR THE VINAIGRETTE
3 tablespoons red wine vinegar
1 tablespoon balsamic vinegar
1 clove garlic, finely chopped
1 teaspoon Dijon mustard
1 teaspoon dried thyme
Salt and ground pepper to taste
2/3 cup extra-virgin olive oil

Preheat an oven to 400°F. Lightly oil 2 large baking sheets. Arrange the eggplant and bell peppers, cut sides down, on 1 baking sheet. Arrange the mushrooms and squash on the second baking sheet. In a small bowl, combine the oil and garlic and brush lightly over the vegetables. Roast the mushrooms and squash until lightly browned on the bottoms, about 15 minutes. Turn and roast the other side, about 10 minutes longer. At the same time, roast the eggplant and peppers until browned on one side, about 25 minutes. Turn and brown the other side, about 20 minutes longer. Remove all the vegetables from the oven. Transfer the peppers to a work surface, drape loosely with aluminum foil, and let cool, then peel off the charred skin. Let all the vegetables cool.

Meanwhile, arrange the leeks in a baking dish. Add the water and drizzle with a little of the remaining oil-garlic mixture. Cover tightly and bake until very tender, 25-30 minutes. Remove from the oven and let cool. Place the spinach on a steamer rack over simmering water, cover, and steam until wilted, about 2 minutes. Transfer to a sieve and press down to extract the moisture. Chop coarsely.

Reduce the oven temperature to 350°F. Lightly brush a 1 1/2-qt glass loaf dish with any remaining oil-garlic mixture. Sprinkle all of the vegetables with salt and pepper. Arrange the pepper halves in the bottom of the prepared dish, cut sides up. Arrange the squash slices on top in a single layer. Sprinkle with half of the torn basil, top with the spinach, and then with the cheese. Arrange the mushrooms in a layer, and top with the leeks. Sprinkle with the remaining basil. Top with the eggplant slices, slightly overlapping them. Cover with foil and press down to compact the vegetables. Bake until heated through, about 30 minutes. Remove from the oven but do not uncover. Let stand for about 30 minutes before serving.

To make the vinaigrette, in a bowl, whisk together the vinegars, garlic, mustard, thyme, salt, and pepper. Slowly whisk in the oil.

Loosen the sides of the terrine, then unmold onto a cutting board. Cut into thick slices and serve atop a spoonful of vinaigrette. Garnish with basil, if desired. Pass the remaining vinaigrette at the table.

Serves 8.

[Holiday Celebrations, Williams-Sonoma Lifestyle Collection]